A030091 Primes such that p and p^2 have same set of digits.

94583, 100469, 102953, 107251, 110923, 184903, 279863, 285101, 406951, 459521, 493621, 499423, 504821, 684581, 752681, 758141, 758941, 786431, 836291, 843701, 928637, 976513, 980261, 1008947, 1009859, 1024399, 1029647

Offset

1,1

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Formula

Equals A000040 INTERSECTION A029793. - Jonathan Vos Post, Jul 06 2008

Mathematica

Select[Prime[Range[82000]], Union[IntegerDigits[#]]== Union[ IntegerDigits [#^2]]&] (* Harvey P. Dale, Aug 12 2011 *)

Prog

(PARI) isA030091(n)=isprime(n)&&Set(Vec(Str(n)))==Set(Vec(Str(n^2))) \\ Charles R Greathouse IV, Jun 28 2011
(Haskell)
import Data.List (nub, sort)
import Data.Function (on)
a030091 n = a030091_list !! (n-1)
a030091_list =
   filter (\x -> ((==) `on` (nub . sort . show)) x (x^2)) a000040_list
-- Reinhard Zumkeller, Aug 11 2011

Crossrefs

Cf. A000040, A029793.

Sequence in context: A348021 A248067 A252323 * A128376 A216122 A206411

Adjacent sequences: A030088 A030089 A030090 * A030092 A030093 A030094

Keyword

nonn,base,nice

Author

Patrick De Geest

Status

approved